Patent GB-742230-A (GB)
Title: Constant pressure pulp presses
IPC: B30B9/12
Filed: 1953-12-14
Abstract: 742,230. Presses for separating liquids from solids. JACKSON & CHURCH CO. Dec. 14, 1953 [Jan. 16, 1953; Sept. 11, 1953], No. 34757/53. Class 46. In a pulp press having a vertically-arranged cylindrical outer wall there are provided a perforated casing spaced from and within the wall, a downwardly-diverging rotary spindle arranged concentrically within the perforated casing and journalled for rotation around its vertical axis, the spindle being provided with a plurality of discontinuous flights arranged substantially spirally but having points of discontinuity to clear resistors extending inwardly from the perforated casing, an outlet orifice at the lower end of the press defined by a pair of mutually facing outlet surfaces, one of which defines a conical surface arranged symmetrically around the spindle axis, and means urging the conical surface toward the other outlet surface under a selectable pressure which is constant and uniform in all positions of the conical surface. A spindle 10 supported between bearings 18 and 82 is rotated by a gear 9 within a perforate screen 12 located in turn inside an outer wall 14. Resistors 28 extend through a frame comprising members 13 surrounding the screen 12 and spaced flights 11 are provided on the spindle 10. Liquid forced through the screen is collected in a trough 16 whence it flows eventually to a conduit 46. Extruded solids pass between, on the one hand, an inner trough ring 39 and conical inner plate 37 and, on the. other hand, a skirt 86 forming the end of the spindle 10 and a wedge ring 61 constrained to slide up or down the skirt by hydraulic mechanism 71. In its uppermost position the ring 61 co-operates with a bevelled surface 41 on the lower inner edge of the trough ring 39 to close the discharge outlet. The ring 61 is supported by a structure 50 comprising three braced arms 51 radiating from a hub 52 and upstanding legs 53, Fig. 3, each stiffened by a brace 54, the legs terminating in a cylindrical housing 58 from which extends inwardly a conical member 60 having a skirt 62. The hub 52 is secured to the plunger 70 of a pressure cylinder 71 supplied with pressure fluid through a manual pressure-controlling valve 69, a directional valve 74 and one of the conduits 72, 73, the ring 61 being thereby moved upward or downward ; for any one setting of the valve 69 the fluid pressure in 71 remains constant. The pressure thus applied to the member 60 is constant and uniform in all positions of the member. The skirt 62 slides within a wall 77, Figs. 1 and 3, guided by a member 78 at the top of the wall, the wall 77 and a plate 76 constituting a chamber 75 for collecting liquid which has passed inward through the spindle 10, when perforated, and through a spider 17. Such liquid passes through a conduit 32 to the conduit 46. The solids pass from between members 37 and 61 to the annular space between an outer housing 29 and an inner housing 31, Figs. 2 and 3, between which brackets 4, 5 are secured, but are constrained by shield plates 33, 33a, 33b, 33c to pass thence to openings 91, 92, Fig. 3, between the edges of a base plate 25 and the housing 29.